In recent years, a fuel cell vehicle (FCV) has been developed. The FCV has a fuel cell to cause a chemical reaction of hydrogen and oxygen so as to generate electric energy. The FCV consumes the generated electric energy to activate a motor so as to obtain driving force of the vehicle. The FCV is connected with a feed pipe in a hydrogen station to supply hydrogen (fuel) to the FCV through the feed pipe. So as to efficiently charge hydrogen, it is desirable to charge high-pressure hydrogen to the FCV. However, in view of safety, monitoring of a temperature and a pressure of a hydrogen tank of the FCV is required when hydrogen is charged to the hydrogen tank. In addition, control of a supply pressure of hydrogen is required in the hydrogen station according to the monitored temperature and the monitored pressure when hydrogen is charged. Therefore, a communication system for transmitting a temperature and a pressure monitored by the FCV to the hydrogen station is needed. For example, such a communication system may employ an electric wave communication or an infrared communication (see JP-A-2009-10682).
In general, the directivity of an electric wave is low, and an electric wave may easily diffuse around. Therefore, when multiple FCVs perform an electric wave communication in a hydrogen station, interference may arise in the electric wave communication. On the other hand, the directivity of infrared ray is high. Accordingly, in an infrared communication system, the optic axis of an infrared communication device of the FCV needs to coincide with an infrared communication device of the hydrogen station so as to perform an infrared communication. The optic axis of an infrared communication device of the FCV is changed in dependence upon the position and the direction of the FCV. Therefore, it is hard to adjust the optic axis of the infrared communication device of the FCV to coincide with the optic axis of the infrared communication device of the hydrogen station.